Chihiro Kawai is the mother of Sasami and Tenchi Kawai, and she runs the CD-Vision music store. Her background as a former successful pop singer heavily influences her present-day life, as she retains a passionate and all-consuming love for karaoke. This hobby is not a private one; she frequently insists that her daughter Sasami sing with her, often to Sasami's visible embarrassment and annoyance. Her enthusiasm for karaoke is portrayed as an extreme addiction, leading her to take drastic actions such as raiding the cash register to purchase an expensive personal computer, which she mistakenly believes is a high-tech karaoke machine. This intense passion defines her core personality: she is cheerful, boisterous, and largely self-absorbed when it comes to her musical interests, though her role as a mother is a key part of her identity.

Her primary motivation in the story is simply the pursuit of her love for singing. This drive creates comedic conflict for her family, particularly when her equipment malfunctions due to the schemes of the antagonist Pixy Misa. When the karaoke software is corrupted, Chihiro suffers from extreme withdrawal symptoms, a state so severe that her employees, Kiyone and Mihoshi, are left to manage her while Tenchi and Sasami travel to Akihabara to find replacement software. In this way, her personal obsession often serves as a catalyst for the plot, placing her at the center of a subplot even as the main magical girl action unfolds elsewhere.

Chihiro's most significant relationship is with her daughter, Sasami. As the owner of the music store, she is also the employer of Kiyone and Mihoshi, who work for her. Her character remains largely static within the original OVA continuity; she does not undergo a significant personal transformation or character arc, functioning instead as a consistent source of comic relief and domestic chaos. However, her role is recontextualized in the alternate continuity of the television series Magical Project S. In that version, she has no familial relationship with Sasami or Tenchi but is recruited as a member of Team Lovely Madams, a group formed to assist the villainess Pixy Misa. In this incarnation, she is known as Mrs. Si, and her karaoke singing becomes a formidable weapon. Her signature song, Ai no Makeikusa (Losing the Fight of Love), is her biggest hit and is featured prominently in the original OVA. Her abilities, while not magical in her primary OVA depiction, are defined by her powerful and captivating singing voice. In Magical Project S, this talent is exaggerated into a destructive sonic attack capable of obliterating a fleet of warships, showcasing the raw power of her vocal prowess.